DiY LED - Cree CXA3070

[Mellodrama]

No. The type of connector is a secondary concern when you're discussing the "flatness" of the heatsink. What we want here (and it wouldn't matter one bit if we're talking an Intel Core i7 processor or a COB) is two surfaces that meet up across the entire contact patch. You want zero dimples, bumps, ripples, gouges, burrs, etc. Ideally the two surfaces would mate up as evenly as possible so that a very thin layer of thermal paste could be used.

A Molex or Ideal holder will help or hinder the heat transfer, depending on how evenly it applies downward pressure. No matter what holder you used, a perfectly flat and smooth heat sink underneath your holder is still better than one that isn't.

 

[mauricem00]

yeah I'm not finished with them yet. What would you suggest for a smooth surface? I was thinking of using steel wool.

aluminum used in heat sinks is very soft you can plane them with a safety razor.(the kind used in box cutters) you can buy a razor plane at most hobby shops. this is faster than using sandpaper and gives a very smooth surface. steel wool or sandpaper leaves scratches that need to be removed with finer sandpaper and does not give you a flat reference to work with.a razor has a very straight edge and shaves the surface leaving no tooling marks.

 

[mauricem00]

That sounds awesome! 2700K all on its it own?


I normally fim them at about 12" but it depends on the plant. If it is a bushy one I try to get them as tall as I can in the veg time that I have. If they are a stretcher Il fim the early and Ill pinch the tallest tops during veg if necessary.

The shadows in that pic were from a sinle light source, 4000K headlamp. Normally in the grow area they get light from lots of different angles but any lower branches that are shaded out I try to cut them off in the first 3 weeks.

I had not considered using led side lighting. commercial lights provide light from the top only but with multiple lights and heatsinks mounting them off center pointed at an angle toward the plants makes a lot of sense.thank you for your input.

 

[bondoman]

aluminum used in heat sinks is very soft you can plane them with a safety razor.(the kind used in box cutters) you can buy a razor plane at most hobby shops. this is faster than using sandpaper and gives a very smooth surface. steel wool or sandpaper leaves scratches that need to be removed with finer sandpaper and does not give you a flat reference to work with.a razor has a very straight edge and shaves the surface leaving no tooling marks.

great idea, I'll give that a try. Last week I just happened to buy a razor scraper that should work perfectly.

 

[Mellodrama]

Tell us how that goes. I've never heard of working aluminum using a plane. It's usually milled, ground and/or sanded. I can't imagine trying to do it with a plane.

 

[CobLedz]

Here is my very first DIY COB LED

I put the spectrometer on this and the mix could not be more perfect.

Peaks at 440 and 660

Chip was 6.00

driver was 20.00

heat sink was 5.00

Fan from thrift store was 5.00

I am going to give it to a grower friend to use as supplemental side lighting.

I will have spectrometer video up soon

 

[mauricem00]

Tell us how that goes. I've never heard of working aluminum using a plane. It's usually milled, ground and/or sanded. I can't imagine trying to do it with a plane.

the aerospace industry developed a lapping compound that is made up of 30 mil lab grown sapphire platelets suspended in cutting oil that planes surfaces on very hard metal when a very close fit is needed. corbon sells it as a bore lapping compound for precision gunsmiths as a replacement for the old lead slug lapping technique. I have used it on 4140 chrome molly steel to remove tooling marks and "high spots" and found it much faster than slug lapping and just as smooth and bright of a finish,planing is replacing sanding in application where very close tolerance fit is needed.I use a safety razor on my heatsinks and it works very well.just keep the cut angle shallow and do not use to much pressure or you will gauge the metal

 

[bondoman]

the aerospace industry developed a lapping compound that is made up of 30 mil lab grown sapphire platelets suspended in cutting oil that planes surfaces on very hard metal when a very close fit is needed. corbon sells it as a bore lapping compound for precision gunsmiths as a replacement for the old lead slug lapping technique. I have used it on 4140 chrome molly steel to remove tooling marks and "high spots" and found it much faster than slug lapping and just as smooth and bright of a finish,planing is replacing sanding in application where very close tolerance fit is needed.I use a safety razor on my heatsinks and it works very well.just keep the cut angle shallow and do not use to much pressure or you will gauge the metal

oh sure now you tell me after I put a couple small holes that weren't there overall it worked pretty good, I just finished it up with metal polish.

 

[DiyKindaGuy]

Cool will yu post a pic

★★★kushed_out★★★

 

[mauricem00]

oh sure now you tell me after I put a couple small holes that weren't there overall it worked pretty good, I just finished it up with metal polish.

sorry I forget sometimes that not everyone who attempts to do metal work does not have formal training in it.turtle wax chrome polish on a buffing wheel should give you a finish you can see yourself in. leds have a large surface area soa few small nicks should not hurt as long as there are no burrs. we all learn from experience and get better with practice. if I told you some of the mistakes I made while learning you would not be able to stop laughing.

 

[SupraSPL]

COBLEDZ, very cool design! I love the idea of moving side lighting that also provides the circulation (I spend 55W of circulation from a ceiling fan). You didnt ask for constructive criticism but I have to warn a fellow grower, a $6 COB running at full blast is probably less than 15% efficient and the COB will suffer significant lumen depreciation over time and may actually burn out, meaning you would be much better off to use HPS which is 36% efficient. A few tweaks to the design and you could be up to 40% with 3000K LED that will last indefinitely.

 

[SNEAKYp]

Jesus, talk about a heatsink CobLedz! Haha very different. It's cool though

 

[DiyKindaGuy]

Neat idea... its awesome watching all the ideas/designs develop

★★★kushed_out★★★

 

[mauricem00]

any opinions on using led strip lights for side lighting. they are only about as efficient as CFLs (64 lumens per watt) but are available in blue,red,ww and cw. the warm whites produce a lot of deep red that is not available with CFLs. and they have adhesive backing so they can be attached to the walls of a small grow room and take up no space. they do not require heat sinks. I know this thread is about trying to beat the efficiency of HPS. but I am a T5HO grower who caught the LED bug and believe that spectrum and cost is as important as efficiency.using a 70 volt 650 ma. driver you can drive 2 50 watt leds in series at 21 watts each. all leds suffer from droop and even cheap chinese leds show a large improvement in efficiency when operated at low power these 50 watt diodes are rated for a maximum current of 2100ma at 34 volts (71 watts) so the 50 watt rating is conservative to begin with. there are others here who have used T5HO aquarium bulbs and I would like to know what improvement they saw (grams per watt) when they switched to leds

 

[mauricem00]

Hey Bueno I am currently using the 4200k XM-L2's as part of my veg cabinet. Running at 1500mA. Amazing growth i must say. (Been under them about a week)

I have also got what you mentioned in my flowering cabinet. Running the 4200k at 700mA on passive heatsink bars as a supplemental lighting to my main COB's and multi-chips.

View attachment 3128784

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Just been sprayed....

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Just re-veging a couple of my outdoor buds

great setup. those cooling plates look massive. how thick are they? looks like they must weigh a few hundred pounds. but I like the way you have your lights spead out

 

[Chronikool]

any opinions on using led strip lights for side lighting. they are only about as efficient as CFLs (64 lumens per watt) but are available in blue,red,ww and cw. the warm whites produce a lot of deep red that is not available with CFLs. and they have adhesive backing so they can be attached to the walls of a small grow room and take up no space. they do not require heat sinks. I know this thread is about trying to beat the efficiency of HPS. but I am a T5HO grower who caught the LED bug and believe that spectrum and cost is as important as efficiency.using a 70 volt 650 ma. driver you can drive 2 50 watt leds in series at 21 watts each. all leds suffer from droop and even cheap chinese leds show a large improvement in efficiency when operated at low power these 50 watt diodes are rated for a maximum current of 2100ma at 34 volts (71 watts) so the 50 watt rating is conservative to begin with. there are others here who have used T5HO aquarium bulbs and I would like to know what improvement they saw (grams per watt) when they switched to leds

Yes ive used (am still using) the LED strips...they do work. And i think they would make great side lighting. Go for the 5630's/5730's or the newer 7020's (if you can find them in warm white)

if you can find any relevance or information in this thread...have a gander >>>>>> https://www.rollitup.org/t/chronikoolz-stripped-lite-peep-show.567470/

great setup. those cooling plates look massive. how thick are they? looks like they must weigh a few hundred pounds. but I like the way you have your lights spead out

Thank you. I like the flat look in a heatsink now....(havent seen it before...probably not the best then... ) and i can find aluminium plates easy...locally. The plates measure 350mm x 350mm by 5mm (thick) Nah not that heavy at all. The area of them does help to disperse the light better, and they also stop any reflected light going to space

 

[mauricem00]

Yes ive used (am still using) the LED strips...they do work. And i think they would make great side lighting. Go for the 5630's/5730's or the newer 7020's (if you can find them in warm white)

if you can find any relevance or information in this thread...have a gander >>>>>> https://www.rollitup.org/t/chronikoolz-stripped-lite-peep-show.567470/



Thank you. I like the flat look in a heatsink now....(haven't seen it before...probably not the best then... ) and i can find aluminium plates easy...locally. The plates measure 350mm x 350mm by 5mm (thick) Nah not that heavy at all. The area of them does help to disperse the light better, and they also stop any reflected light going to space

actually heatsinks do not have to be fined. it is the surface area that determines how much cooling they provide. a plate that size should have a thermal coefficient of 0.4 C/W. in english you should see a temperature rise of 0.4 degrees C for every what of power you are dissipating.from the picture and your description you are running about 4.2 watts per led with 11 leds this equals 46 watts which should give you a temperature rise of about 18.4 degrees C above ambient once equilibrium is reached. I like the ideal of distributing light ove a large area by using several 10 watt leds. it seems like it would help get light under the canopy to the lower leaves.
I originally considered warm white strip lights as side lighting for T5 grow lights due to there lack of deep red light.but than I discovered modern P&A bulbs that have a peak at 658 nm and produce a lot of red and deep red light. I think the most intelligent growers use rollitup and have learned a lot from this site. I get a little tired of trying to interpret "stoner" on youtube and some other growing sites LMAO and enjoy the intelligent discussion and the mutual assistance I find here

 

[mauricem00]

CHRONIKOOL I liked the thread you linked me to. I was not aware tht people were using just strip lights to grow.I love the way people experiment here and just have fun with their grows. I found some 5630s on ebay http://www.ebay.com/itm/161242023201?var=460286130422&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 so I ordered a strip to play with. ay 4800-5400 lumen per strip they look pretty efficient. they should be a great way of getting light under the canopy if they work as advertised. I really like your attitude in that thread

 

[mtnstream]

FYI, pc120mm fan copper tim on alum block works well.

 

[Chronikool]

CHRONIKOOL I liked the thread you linked me to. I was not aware tht people were using just strip lights to grow.I love the way people experiment here and just have fun with their grows. I found some 5630s on ebay http://www.ebay.com/itm/161242023201?var=460286130422&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 so I ordered a strip to play with. ay 4800-5400 lumen per strip they look pretty efficient. they should be a great way of getting light under the canopy if they work as advertised.

Nice work. Also dont rely on that adhesive to work on the strips....you will need a third party glue to help there. There were a couple of other 'brothers in crime that were 'strip lighting'.....

Caretak3r (still around the forums) https://www.rollitup.org/t/fun-with-smd-led-strips-5630-and-5050-in-preparation-for-the-bucket-of-light.635171/
Panelata (MIA) https://www.rollitup.org/t/first-time-grower-experimenting-with-cheap-leds.610538/

I really like your attitude in that thread

Yeah...now my attitude is 'grumpy olde fuck'....